Adjustable tread stairs



D. W. FELLOWS.

ADJUSTABLE TREAD STAIRS.

APPLICATION HIJED MAY 26. 1921-.

Patented June 13,1922;

DANIEL W. FELLOWS, OF LOS ANGELES, CALIFORNIA.

' ADJUSTABLE TREAD- STAIRS.

Application filed May 26,

To all whom it may concern:

Be it known that I, DANIEL W. FELLoWs, a citizen of the United States,residing at Los Angeles, in the county of Los Angeles and State ofCalifornia, have invented new and useful Improvements in AdjustableTread Stairs, of which the following is a specification.

It is the object of this invention to provide a stairway, such as isemployed between a boat or dock and any object resting upon.

the surface of water, such as another boat or a float which will riseand fall through changes in the tide.

The present invention provides a stairway of this character wherein therespective treads of the stairway will be maintained parallel and in ahorizontal position irrespective of the swinging movement of thestairway.

The invention will be readily understood from the following descriptionof the accompanying drawings, in which: t

Figure 1 is a vertical section through a stairway constructed inaccordance with the invention.

Fig. 2 is a similar view showing the swinging end of the stairwayelevated as by the lifting of the float upon which said stairway rests,and responsive to a rise in v the tide.

Fig. 3 is a perspective view of one of the treads of the stairway.

Fig. 4 is a similar view showing the uppermost tread of the stairway andthe connections with the same.

The improved stairway is illustrated as pivoted at one end to a dock orthe like shown at 1 and having its opposite lower end resting on a float2 upon the surface of water 3. The float will rise and fall responsiveto variations in the tide, and as a consequence the stairway will beswung up and down with relation to dock 1. The treads of the stairwayare arranged to be maintained parallel and horizontal irrespective ofthe position of the stairway.

As an instance of this arrangement, an upper tread 4 is pivoted todock 1. This tread is shown as provided with a rear depending bracket 5,and a pivot rod 6 extends through the bracket and is journaled in eyebolts 7 carried by the dock.

Specification of Letters Patent.

Patented June '13, 1922.

1921. Serial No. 472,644.

The tread is normally fixed in horizontal position as by a bolt 8received through a slot 9 in bracket 5 and threaded into the dock 1.When, however, there is a possibility of the stairway swinging above thehorizontal position, the bolt 8 is removed so that tread 4 is free forswinging movement upwardly by means of pivot rod 6 journaled in eye bolt7. When the stairway is arranged for normal use i. e.: with the sameextending downwardly from its lowermost tread 4, the latter is fixedagainst the side of the dock by means of bolt 8, and in this positionthe bracket 5 abutting against the side of the dock will form a bracefor the tread 4.

Two side rails 12 and 13 are arranged at each side of the stairway, therails being pivoted to bracket 5, as shown at 14, and the side rails 13being pivoted to ears 15 extending upwardly from the front edge of tread4.

The treads forming the length of the stairway each comprise a treadplate 16 having depending cars 17 at the respective sides of the rearedge of the same and having upturned ears 18 at the respective sides ofthe front edge of the tread plate. The tread plates 16 are pivoted toside bars 12 by means of pins extending through said side bars and thecars 17, and the tread plates are similarly pivoted to side bars 13 bypins extending through the cars 18 and said side bars.

It will be understood that the tread plates 16 are so arranged betweenside bars 1213 as to position said tread plates parallel to one anotherand to tread plate 4, and that as a consequence the tread plates 16 willlie in horizontal planes. The stairway is supported upon float 2 bymeans of suitable rollers 20 upon the lower ends of side rails 12, andas a consequence the stairway is free for movement relative to thefloat, and as the latter rises the side rails 12 and 13 will approach ahorizontal position, but the tread plates pivoted between the same willmaintain their parallel positions in horizontal planes so as to form aconvenient stairway.

Various changes may be made without departing from the spirit of theinvention as claimed.

What is claimed is:

A stairway comprising a bracket having a tread portion, downwardly andback; vvardly extendingside flanges and upward 5 ly and forwardlyextending ears, rails piv-' otally connected to;- the: side; flanges;-rails pivotally connected to the ears, and tread plates having dependingears attheir-reansides pivotally connected to the first rails and havingupwardly extending ears at their 10 front sides ::and pivotallyconnected to the second rai1s'.-

In testimony whereof I have signed my nam o this specification DANIEL W.FELLOWS.

